Well the scorpion tank gets charged by some pillar like structures every time it loses 20-25% of its power. So when it starts to charge, the forcefield surrounding the structures gets open. Blast the structures and then try to kill the scorpion tank via normal means.

The stage was very hard for me. It took me and hour and half to retry a couple of times and finish it.

Life is best for those who enjoy it, difficult for those who analyze it and worst for those who criticize it.